固相萃取-高效液相色谱-二极管阵列检测法测定原料乳中三聚氰胺

原料乳经三氯乙酸和乙腈提取，高速离心后取上清液，用阳离子交换固相萃取小柱净化后，以乙腈一庚烷磺酸钠缓冲液作流动相，采用AgilemZorbax300-SCX250×4．6mm色谱柱分离，高效液相色谱一二极管阵列检测器（HPLC-DAD），外标法定量。方法线性范围0．005-5．00gg／mL，相关系数r〉0．9999，加标回收率为103．6％-105．2％，RSD为O．26％，保留时间在6．82min左右，检出限为O．5mg／kg。该方法简单、快速，适用于大批量样品的快速检验和乳制品出厂检验。

A Fast analysis of melamine in raw milk with high performance liquid chromatography

The raw Milk is extracted by trichloroacetic acid and acetonitrile, then by high speed centrifugaten and raked the supernatant.The supernatant is purificated with the cation exchange solid phase extraction column. Asa mobile phase of acetonitrile - heptane sulfonate buffer, then separated used Agilent Zorbax 300-SCX 250× 4.6mm and the mobile phase consisted of acetonitrile-sodium heptanesulfonate, finally analyzed by HPLC with photodiode array detector （ HPLC-DAD ）. Results the linear range of calibration curveswere in rang of 0.005 ~ 5.00 gg/mL, the correlation coefficient r 〉 0.9999, the recovery of standard addition were in rang of 103.6%-105.2%, the relative standard deviation （ RSD ） was 0.26% and the limits of detection were lmg/kg formilk powder and 0.5 mg/kg for Raw milk, Conclusion the results showed this method was simple and rapid and it is adaptable to detectmelamine in these products for factory inspection.